The present invention relates to a method for making sulfonated aromatic organic polymer having aminoorganomercaptan groups attached to backbone sulfonyl radicals by covalent nitrogen-sulfur linkages. More particularly, the present invention relates to a method of covalently bonding by nitrogen-sulfur linkages certain aminoorganothioethers to sulfonated aromatic organic polymer, and thereafter cleaving the resulting covalently bonded thioether groups to the corresponding mercaptans.
Prior to the present invention, as shown by Faler et al, U.S. Pat. Nos. 4,294,995 and 4,346,247, sulfonated polystyrene ion-exchange resins having organo mercaptan groups attached to backbone sulfonyl radicals by covalent nitrogen-sulfur linkages, were made by modifying halosulfonyl aromatic organic polymers, such as chlorosulfonyl polystyrene with aminoorganodisulfide to produce an intermediate sulfonated polystyrene resin having covalently bonded aminoorganodisulfide groups. The aforementioned ion-exchange precursor was treated with a reducing agent, such as a triorganophosphine, to convert the disulfide to an organo mercaptan.
Improved results were achieved as shown by copending application Ser. No. 342,435, Faler et al, filed Jan. 25, 1982 using the aminoorganodisulfide method which was thereafter reduced to the corresponding organo mercaptan group. Additional procedures for making ion-exchange resins are taught in foreign patent documents such as 23325, 7/1980, European Patent Office, 2,733,537, 2/1978, 2,931,036, 2/1981 Federal Republic of Germany.
The present invention is based on the discovery that aminoorganothioethers of the formula ##STR1## where R is selected from hydrogen and a C.sub.(1-8) alkyl radical, R.sup.1 is a divalent C.sub.(1-13) organic radical, R.sup.2 is a cleavable organic radical and preferably acid cleavable organic radical and Y is selected from hydrogen, carboxy and nitrile, can be reacted with a halosulfonyl aromatic organic polymer, such as chlorosulfonyl polystyrene ion-exchange resin to produce a sulfonated aromatic organic polymer having aminoorganothioether groups attached to backbone sulfonyl radicals by covalent nitrogen-sulfur linkages. The covalently bonded aminoorganothioether groups thereafter can be cleaved under acidic conditions to produce the corresponding sulfonated aromatic organic polymer having covalently bonded aminoorganomercaptan groups. The resulting ion-exchange resin can be used to effect phenol-ketone condensation in the synthesis of bisphenols.